TITLE: GCN CIRCULAR NUMBER: 41513 SUBJECT: GRB 250823A: BOOTES6/DPRT early optical detection DATE: 25/08/23 23:11:13 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es> E. Fernandez-Garcia, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy, S.-Y. Wu and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, Bloemfontein), A. Martin-Carrillo and L. Hanlon (UCD, Dublin), C. J. Perez del Pulgar (UMA, Malaga), Y.-D. Hu (GXI, Guangxi) and M. Gritsevich (Univ. of Helsinki), on behalf of a larger collaboration, report: Following the detection of GRB250823A by Fermi (Fermi GBM Team, GCN Circ. 41510) and Swift/BAT (Siegel et al., GCN Circ. 41511), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) automatically observed the Swift/XRT X-ray afterglow location starting on Aug. 23, 20:12:44 UT (i.e. 157 s after trigger). A series of images in clear filter were gathered and the optical counterpart reported by the LT (Gompertz et al., GCNC 41512) was detected at early times in our dataset. We measure a preliminary magnitude of 19.30 +- 0.15 on the co-added 10 s x 45 image (at 20:28:26 UT mid time). Further data analysis is ongoing. We thank the staff at Boyden Observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/41513. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...